Detection of unidentified chromosome abnormalities in human neuroblastoma by spectral karyotyping (SKY).
ABSTRACT Spectral karyotyping (SKY) is a novel technique based on the simultaneous hybridization of 24 fluorescently labeled chromosome painting probes. It provides a valuable addition to the investigation of many tumors that can be difficult to define by conventional banding techniques. One such tumor is neuroblastoma, which is often characterized by poor chromosome morphology and complex karyotypes. Ten primary neuroblastoma tumor samples initially analyzed by G-banding were analyzed by SKY. In 8/10 tumors, we were able to obtain additional cytogenetic information. This included the identification of complex rearrangements and material of previously unknown origin. Structurally rearranged chromosomes can be identified even in highly condensed metaphase chromosomes. Following the SKY results, the G-banding findings were reevaluated, and the combination of the two techniques resulted in a more accurate karyotype. This combination allows identification not only of material gained and lost, but also of breakpoints and chromosomal associations. The use of SKY is therefore a powerful tool in the genetic characterization of neuroblastoma and can contribute to a better understanding of the molecular events associated with this tumor.
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ABSTRACT: Gain of genetic material from chromosome arm 17q (gain of segment 17q21-qter) is the most frequent cytogenetic abnormality of neuroblastoma cells. This gain has been associated with advanced disease, patients who are > or =1 year old, deletion of chromosome arm 1p, and amplification of the N-myc oncogene, all of which predict an adverse outcome. We investigated these associations and evaluated the prognostic importance of the status of chromosome 17. We compiled molecular cytogenetic analyses of chromosome 17 in primary neuroblastomas in 313 patients at six European centers. Clinical and survival information were collected, along with data on 1p, N-myc, and ploidy. Unbalanced gain of segment 17q21-qter was found in 53.7 percent of the tumors, whereas the chromosome was normal in 46.3 percent. The gain of 17q was characteristic of advanced tumors and of tumors in children > or =1 year of age and was strongly associated with the deletion of 1p and amplification of N-myc. No tumor showed amplification of N-myc in the absence of either deletion of 1p or gain of 17q. Gain of 17q was a significant predictive factor for adverse outcome in univariate analysis. Among the patients with this abnormality, overall survival at five years was 30.6 percent (95 percent confidence interval, 21 to 40 percent), as compared with 86.0 percent (95 percent confidence interval, 78 to 91 percent) among those with normal 17q status. in multivariate analysis, gain of 17q was the most powerful prognostic factor, followed by the presence of stage 4 disease and deletion of 1p (hazard ratios, 3.4, 2.3, and 1.9, respectively). Gain of chromosome segment 17q21-qter is an important prognostic factor in children with neuroblastoma.New England Journal of Medicine 07/1999; 340(25):1954-61. · 51.66 Impact Factor
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ABSTRACT: We ascertained a newborn girl with multiple congenital anomalies including severe hypotonia, cardiovascular defects, hearing loss, central nervous system anomalies, and facial anomalies. The infant died at 12 days. Cytogenetic analysis showed a de novo supernumerary marker chromosome. Fluorescence in situ hybridization (FISH) with a combination of chromosome specific alpha-satellite probes and an all-human centromere probe failed to show hybridization to the marker, indicating that the marker chromosome lacked detectable alpha satellite sequences. Spectral karyotyping (SKY) was performed and showed that the marker was chromosome 15 in origin. This was confirmed by FISH with a 15q specific subtelomerie probe, which showed hybridization to both ends of the marker chromosome. Based on FISH information and G-banding pattern, the marker was determined to be an inverted duplication of 15q25-qter, leading to partial tetrasomy for chromosome 15. Although the marker chromosome lacked detectable centromeric alpha-satellite sequences, it seemed to have a functional centromere as it is mitotically stable. This observation is consistent with previous studies on acentric marker chromosomes, which suggested that the DNA sequence at the breakpoint could function similarly to alpha-satellite sequences once activated through marker formation.American Journal of Medical Genetics 01/1999; 80(4):368-72.
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ABSTRACT: Immunocytologic analyses of bone marrow can provide clinically useful prognostic information in neuroblastoma. While analyzing the bone marrow with a panel of monoclonal antibodies, which detect neuroblasts and other defining B-, T-, and myloid lineage, we identified two infants with stage IV-S neuroblastoma whose bone marrow contained a large population of common acute lymphoblastic leukemia (ALL)-like cells. This population expressed HLA-DR, CD19(B1), CD10(CALLA), and occasionally CD20(B1). Since 1988, 17 additional patients with advanced neuroblastoma (IV-S, III, and IV) were studied by us. In 10 of the 19 patients, the bone marrow revealed an expanded CD10 population (20-70%). It appears that this group of patients has a better prognosis. Out of 9 patients who did not have an expanded CD10 population, 8 died within 9 months from diagnosis, whereas out of 10 patients with an expanded CD10 population only one died and the others are alive, 6-30 months from diagnosis (P < 0.001). An expanded CD10 population in the bone marrow of disseminated neuroblastoma patients may therefore serve as a prognostic factor. Apart from the prognostic value of this particular population in the single patient, its presence may shed light on the interrelationship between the immune system and the neuroendocrine compartment.Medical and Pediatric Oncology 01/1994; 22(2):115-8.